[PATCH] D144468: [GlobalOpt] Extend CleanupPointerRootUsers to handle CE users.

[Florian Hahn via Phabricator via llvm-commits]

fhahn created this revision.
fhahn added reviewers: aeubanks, nikic, kubamracek.
Herald added subscribers: ormris, StephenFan, hiraditya.
Herald added a project: All.
fhahn requested review of this revision.
Herald added a project: LLVM.

Extend CleanupPointerRootUsers to iterate over a worklist, add users of
constant expressions to the worklist to enable additional cleanups.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D144468

Files:
  llvm/lib/Transforms/IPO/GlobalOpt.cpp
  llvm/test/Transforms/GlobalOpt/cleanup-pointer-root-users-gep-constexpr.ll


Index: llvm/test/Transforms/GlobalOpt/cleanup-pointer-root-users-gep-constexpr.ll
===================================================================
--- llvm/test/Transforms/GlobalOpt/cleanup-pointer-root-users-gep-constexpr.ll
+++ llvm/test/Transforms/GlobalOpt/cleanup-pointer-root-users-gep-constexpr.ll
@@ -16,21 +16,6 @@
 define void @stores_single_use_gep_constexpr() {
 ; CHECK-LABEL: @stores_single_use_gep_constexpr(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    store ptr @fn1, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR:%.*]], ptr @global.20ptr, i64 0, i32 1), align 8
-; CHECK-NEXT:    store ptr @fn2, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR]], ptr @global.20ptr, i64 0, i32 2), align 8
-; CHECK-NEXT:    store ptr @fn3, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR]], ptr @global.20ptr, i64 0, i32 3), align 8
-; CHECK-NEXT:    store ptr @fn0, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR]], ptr @global.20ptr, i64 0, i32 4), align 8
-; CHECK-NEXT:    store ptr @fn1, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR]], ptr @global.20ptr, i64 0, i32 5), align 8
-; CHECK-NEXT:    store ptr @fn2, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR]], ptr @global.20ptr, i64 0, i32 6), align 8
-; CHECK-NEXT:    store ptr @fn3, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR]], ptr @global.20ptr, i64 0, i32 7), align 8
-; CHECK-NEXT:    store ptr @fn0, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR]], ptr @global.20ptr, i64 0, i32 8), align 8
-; CHECK-NEXT:    store ptr @fn1, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR]], ptr @global.20ptr, i64 0, i32 9), align 8
-; CHECK-NEXT:    store ptr @fn2, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR]], ptr @global.20ptr, i64 0, i32 10), align 8
-; CHECK-NEXT:    store ptr @fn3, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR]], ptr @global.20ptr, i64 0, i32 11), align 8
-; CHECK-NEXT:    store ptr @fn0, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR]], ptr @global.20ptr, i64 0, i32 12), align 8
-; CHECK-NEXT:    store ptr @fn1, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR]], ptr @global.20ptr, i64 0, i32 13), align 8
-; CHECK-NEXT:    store ptr @fn2, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR]], ptr @global.20ptr, i64 0, i32 14), align 8
-; CHECK-NEXT:    store ptr @fn3, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR]], ptr @global.20ptr, i64 0, i32 15), align 8
 ; CHECK-NEXT:    ret void
 ;
 entry:
@@ -56,8 +41,6 @@
 define void @stores_multi_use_gep_constexpr() {
 ; CHECK-LABEL: @stores_multi_use_gep_constexpr(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    store i32 0, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR:%.*]], ptr @global.20ptr, i64 0, i32 16), align 8
-; CHECK-NEXT:    store i32 0, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR]], ptr @global.20ptr, i64 0, i32 16), align 8
 ; CHECK-NEXT:    ret void
 ;
 entry:
Index: llvm/lib/Transforms/IPO/GlobalOpt.cpp
===================================================================
--- llvm/lib/Transforms/IPO/GlobalOpt.cpp
+++ llvm/lib/Transforms/IPO/GlobalOpt.cpp
@@ -206,8 +206,13 @@
   // chain of computation and the store to the global in Dead[n].second.
   SmallVector<std::pair<Instruction *, Instruction *>, 32> Dead;
 
+  SmallVector<User *> Worklist(GV->users());
+  SmallPtrSet<User *, 8> Seen;
   // Constants can't be pointers to dynamically allocated memory.
-  for (User *U : llvm::make_early_inc_range(GV->users())) {
+  while (!Worklist.empty()) {
+    User *U = Worklist.pop_back_val();
+    if (!Seen.insert(U).second)
+      continue;
     if (StoreInst *SI = dyn_cast<StoreInst>(U)) {
       Value *V = SI->getValueOperand();
       if (isa<Constant>(V)) {
@@ -238,7 +243,8 @@
       if (CE->use_empty()) {
         CE->destroyConstant();
         Changed = true;
-      }
+      } else
+        append_range(Worklist, CE->users());
     } else if (Constant *C = dyn_cast<Constant>(U)) {
       if (isSafeToDestroyConstant(C)) {
         C->destroyConstant();


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D144468.499098.patch
Type: text/x-patch
Size: 3981 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20230221/1f2f1aa7/attachment.bin>